Did naughty nun kick the habit?
is a common presentation in general practice, so which of the available treatments work best? Dr Fay Crawford assesses the evidence
Athlete's foot is mostly caused by dermatophytes and occurs between the toes or on the soles, heels and borders of the foot.
In primary care it is diagnosed based on the clinical presentation alone and fissuring, itching and scaling are all signs and symptoms of the superficial fungal infection.
UK estimates suggest athlete's foot is present in 15 per cent of the general population.
Fungal infections are not life or limb-threatening in people with normal immune status or who do not have diabetes mellitus, but dryness, fissuring and cracking can compromise the integrity of the skin and expose individuals to systematic infections.
In the UK at present all antifungal creams are available as over-the-counter medicines and none are prescription only.
Two systematic reviews have evaluated the effectiveness of topical and oral preparations to cure athlete's foot and have produced good evidence from moderate to high-quality randomised controlled trials.
The topical systematic review included 70 randomised controlled trials and the systematic review of oral drugs included 12 randomised controlled trials (Crawford 2005, Bell-Syer 2005).
An additional RCT has been published that compares cure rates between creams and tablets, and provides a small amount of evidence about the relative effectiveness of topical compounds versus oral treatments (Barnetson 1998).
•There is good evidence that all antifungal creams are effective in the eradication of dermatophyte skin infections, but some have higher cure rates than others.
•Most randomised controlled trials have evaluated topical allylamines and azoles, consequently the evidence about the effectiveness of these preparations is the most precise.
•A meta-analysis of data collected in 11 RCTs found a statistically significant difference in cure rates between 1% allylamines cream (Lamisil) and 1%-2% azole creams (eg Canesten, Daktarin). Both types of creams were used for one-two weeks and outcomes collected at six weeks (80 per cent versus 72 per cent).
•RCTs of direct comparisons of allylamines have not detected statistically different cure rates between different allylamines.
•RCTs of direct comparisons of azole creams have not detected statistically significantly different cure rates between different azoles.
•Oral drugs are sometimes recommended for athlete's foot when extensive areas of the skin are involved but data from one RCT comparing oral terbinafine (250mg) versus clotrimazole 1% for interdigital infection did not find a statistically significant difference in cure rates.
•Terbinafine 250mg/daily is more effective than itraconazole 100mg daily or griseofulvin 1000mg/daily.
•Antifungal creams are well-tolerated and systematic reviews have found no evidence of adverse events, unlike oral treatments.
•Tolnaftate (Tinaderm) has been shown
to have poorer cure rates than clotrimazole.
•Undecenoic acid (Mycota) has good cure rates compared with placebo but has not been compared with other topical preparations in an RCT.
•A few patients in the placebo arms of trials of topical compounds have been cured, which suggests improved foot hygiene alone may be enough to eradicate dermatophytes in some people.
What doesn't work?
•In RCTs tea tree oil did not produce a greater benefit than placebo and pro-
duced fewer cures than tolnaftate (see box below).
All topical antifungals are now available as OTC preparations. The relatively high costs of oral antifungal drugs and lack of evidence of their superiority makes topical antifungal preparations the most cost-effective option in the management of athlete's foot.
The bottom line
Allylamines (1%) and azoles (1%-2%) are very effective in the management of athlete's foot. The evidence for tolnaftate (1%) and
undecenoic acid is less robust but suggest these compounds are also effective.
Although it is believed that more recalcitrant disease should be treated with oral antifungal agents, one randomised evaluation comparing topical and oral medication indicates that topical agents and oral drugs have similar efficacy.
Fay Crawford is a health services researcher and a podiatrist for Tayside health board –
she is a contributor to the Cochrane library
and the BMJ's Clinical Evidence librbary and is also an NHS R&D fellow at the University of Dundee, funded by the Chief Scientist Office, the Scottish Executive
what topical preparations work
Comparators Length of Relative risk of failure to cure
treatment (95% CI)
Allylamines versus azoles 6 weeks 2.6 (2.3 to 2.9)
Allylamines versus placebo 4 weeks 3.7 (3.2 to 4.4)
Azoles versus placebo 4 weeks 2.1 (1.85 to 2.3)
Undecenoic acid versus tolnaftate 6 weeks 1.1 (0.42 to 2.68)
Tolnaftate versus undecenoates 6 weeks 1.1 (0.42 to 2.68)Tea tree oil versus tolnaftate 6 weeks 0.8 (2.01 to 10.68)